This invention relates to a vehicle mounted refuse collection apparatus and, more particularly, to a vacuum type collector apparatus especially adapted for use in cleaning out sewers, sludge basins, and the like in which both particulate matter and liquids are present.
For cleaning out sewers, for example, it has proven efficient to have both a collecting or vacuum apparatus and a refuse storage tank combined on a single vehicle and adapted to be transported to the clean-up site, and after clean-up to be transported to a suitable waste disposal site. Examples of such arrangements are disclosed in U.S. Pat. Nos. 4,111,670 of DeMarco, 4,227,893 of Shaddock, 4,199,837 of Fisco, Jr., 4,234,980 of DiVito et al, and 4,160,302 of Hirst et al.
For the heavy duty cleaning out of sewers and the like, it has been found desirable to inject water under pressure into the sewer or element to be cleaned out and the water transports the refuse from the sewer to the storage tank. In most cases the water can be separated from the refuse and discharged from the storage tank to the sewer. To insure an adequate supply of water at the job site, it is desirable to include along with the refuse collecting unit and storage tank a water tank of sufficient capacity. The water tank can be mounted on the vehicle together with a pump and other suitable apparatus for introducing the water from the water tank into the sewer or element to be cleaned. Examples of various arrangements for accomplishing this are shown in the aforementioned Fisco, Jr., DiVito et al, and Hirst et al patents, as well as in U.S. Pat. Nos. 4,207,647 of Masters and 4,322,868 of Wurster.
In the known prior art arrangements, the vehicle is driven to the site where clean-up is to take place, one end of a vacuum hose carried by the vehicle on a boom arrangement is lowered into the sewer and the refuse is vacuumed up through the hose and into the refuse storage tank. Various arrangements are provided within the refuse storage tank for separating the refuse from the air stream so that the tank becomes filled with the refuse and the air is discharged to the atmosphere. When loaded with refuse, the vehicle is transported to a suitable waste deposit site and the entire tank is tilted to empty it. Where water is used to facilitate the cleaning process, means generally are provided to separate the water from the refuse, which allows dumping the water back into the sewer.
All of such systems have shortcomings. For example, the tilting of a refuse laden carrier requires expensive heavy duty tilting mechanisms for raising the front of the refuse storage chamber and which create an electrical shock hazard when in the vicinity of overhead power lines. Where the vehicle is equipped with a water tank, not only is an additional complication produced in the tilting operation, but a problem of weight distribution is presented. In most cases where tilting is used to empty the refuse storage tank, it is necessary to uncouple the hoses or conduits connected to the tank before the refuse tank is tilted.
The weight distribution problem created by the addition of a water storage tank can best be appreciated by an example. Where the water storage tank is mounted in front of the refuse storage tank, as the vehicle is being driven to the collection site, the greatest percentage of the load carried by the vehicle is due to a full water tank, while the refuse tank is empty. This places a higher percentage of the vehicle weight on the front wheels and tends to overload the front wheels. After the clean-up, the opposite situation prevails, since the water tank is now virtually empty and the refuse tank is full, thereby placing the greatest portion of the weight over the rear axle or axles of the vehicle. If the water tank is either above or below the refuse tank, there likely is produced a top-heavy condition, either en route to the site, or en route to the waste dump, which can be dangerous while the vehicle is moving.
In the vacuum process, an air pump is used to create the vacuum, and usually such pump is located at or near the discharge point of the air to the atmosphere. If particulate matter remains in the air stream after passage through the refuse collection tank, the particulate matter can damage or clog the pump, as well as be discharged into the surrounding atmosphere. In an effort to cleanse the discharge air, sometimes filters are use, in some cases comprising a multiplicity of filter bags contained in a housing located between the refuse tank and the air pump. Such an arrangement is shown, for example, in the Shaddock patent. A problem arises with such bags, however, in that they accumulate particulate matter and commence to impede the air flow after a time, thus it is necessary to clean and replace such bags. Replacement of the bags in accordance with prior art methods entails lifting the bags out of the housing, which results in the dislodging and deposit of some of the particulate matter in a region of the housing that is normally in the path of filtered air flow, with the net result that in operation, the discharged air may contain some remnants of the refuse which can damage the air pump.
The prior art vacuum refuse collection vehicles generally are unitary in nature, and, once designed, are limited to the sizes and capacities incorporated in the design specifications. The inflexibility of capacities of the design is likely to result in an arrangement of insufficient capacity for some applications, or of too much capacity for other applications or a mismatch of water storage capacity with refuse storage capacity for a particular job requirement.
It is therefore, an object of the present invention to eliminate the necessity of tilting the entire container assembly, thereby resulting in a relatively simple structure that does not require expensive tilting machinery and does not require disconnection of the various pipes and hoses from the refuse collection tank prior to tilting.
It is another object of the invention to provide a water storage tank on the refuse collection vehicle for carrying a supply of water along with the refuse collecting tank in such a manner that weight shifts and imbalances are minimized and the axial loading of the vehicle remains relatively constant as the water supply is depleted and the waste is collected.
Still another object of the invention is to provide a filter bag housing and bag mounting arrangement that reduces the likelihood of waste matter being deposited in the region of filtered air flow when the bags are removed for replacement or cleaning.
Another object of the present invention is to provide a semi-modular construction for a refuse collecting vehicle whose size and capacity can be customized for the particular use to which the vehicle is to be put.